1. Field of the Invention
This invention relates to novel 3-hydroxypyridine derivatives useful as medicines, a method of producing them and pharmaceutical compositions containing them.
The novel 3-hydroxypyridine derivatives of this invention have smooth muscle relaxation activities, coronary blood flow increasing activities, antihypertensive activities, ischemic cardiomuscular protective activities and lipometabolic ameliorative activities, and have therapeutic (treating) and prophylactic (preventing) effects against, for example, cardiovascular diseases such as angina pectoris, cardiac infarction, cardiac insufficiency, arrhythmia and hypertension; respiratory diseases such as asthma; cerebral diseases such as cerebrovascular contraction, apoplectic stroke and epilepsy; enuresis; peptic ulcer; hypersensitive intestinal disturbances; and alopecia.
2. Description of Related Art
Recently, a new type of drugs called a potassium channel opener exhibiting smooth muscle relaxation activities by opening (activating) the potassium channel has attracted attention. For example, chroman-3-ol derivatives which have the potassium channel opening (activating) activity and exhibit antihypertensive activity on spontaneous hypertensive rats are disclosed in JPA S58(1983)-67683 corresponding to EPA 76075, J. Med. Chem., 29, pp. 2194-2201 (1986) and Br. J. Pharmac. 88, pp. 103-111 (1986). In U.S. Pat. No. 4,057,636, cyanoguanidine derivatives having antihypertensive activities is disclosed. However, 3-hydroxy pyridine derivatives having potassium channel opening activities have not been known yet.